While that can be bad, sometimes you come out ahead after accounting for spoilage, time, and travel.

Sometimes I pay higher unit prices at a dollar store intentionally because they offer smaller package sizes not offered elsewhere and I only need the smaller amount. I could get a much better unit price at another store but would waste the rest of the product.

I lived for an entire year out of just Dollar General and Dollar Tree. In some rough areas they are the only stores where you can buy groceries, so they have very clear monopolies. There are good value products, and like everything these days you have to use their apps to get the best offers. Also, the Dollar General app lets you check the price of everything before you take it to the counter. They regularly have items marked up at 1 cent.

Saying it only targets the vulnerable because of high unit prices is like saying the local gas station is a rip off that only targets the vulnerable because prices are higher.

I lived in a city that’s in North Metro Atlanta (Johns Creek) where the median household income was $160K. There was a Dollar General right by a Publix. People still went in the Dollar General for little things where the small packages that you could buy was feature and not a bug.

We still stop by the dollar store for snacks sometimes because it is convenient just to get things to pack for a flight. It’s especially popular for tourists in Orlando where I live

The "dollar stores" vary.

I've been able to find good deals on some things at Dollar Tree. Usually the good deals were a smaller quantity of a normal-quality brand-name item. I mostly avoid the substandard quality items. But even sometimes substandard is OK if, say, you want to make your political demonstration sign on white foamcore (much cheaper than the art supply store, and you don't care if it's smaller, thinner, or outgassing) rather than on an Amazon shipping box.

There was a Family Dollar across from a large public housing project here, where I also went looking for deals, but the shelf prices looked like a convenience store. I didn't find out whether they were fraudulently charging even more at the register like this article describes. (I hope it closed because the residents knew there was an affordable Market Basket a 20-30 minute walk away, over the city line and train tracks, and they were able to get there and find the time for it.)

Have you ever been to a dollar store? Its much cheaper for the same items than a regular grocery store. Also not everyone needs a Costco sized tub of mayo. You test it yourself go by a standard sized candy bar at safeway/alberstons and then at a dollar store. Bottle of coke. Birthday card. Better yet compare the cost spices. Try to buy bay leaves at regular grocery store for under $5.

time value of money

we don’t complain that the per unit cost at target is higher than at costco

People usually understand this, but realize driving 10 minutes to dollar tree for a few items is preferable to driving 30 minutes to cheaper shop

> The list price is low but the per-unit price is astronomical compared to grocery store prices.

The problem is, so is material cost and handling effort. Say, a 2 liter bottle of soda compared to 10x 200 mL. Same amount of soda, but more handling required for stocking, inventory management (aka, make sure there is no soda expiring on the shelf) and finally scanning it over the cash register, and more packaging material.

Larger units of anything will always be cheaper than small units.

Yup. Dollar General is worse than a convenience store like 7-11, it's an expensive inconvenience store.

And we need more local co-op grocery stores like Berkeley Bowl, the Davis Co-op, and ATX Wheatsville.